LAKOS STS SERIES SAND FILTER

Sample Specifications – CSI Format

Part 1 – General

1.01 Purpose

  1. The following specified equipment will help prevent particle fouling of the cooling system’s componentry, reduce maintenance and servicing routines, maintain optimum energy efficiency of the heat exchange process, limit water loss & chemical use practices and control harmful bacteria growth in the basin/sump.
  1. Equipment for this purpose shall be a LAKOS STS Tower System Sand Filter Package as manufactured by Claude Laval Corporation.

1.02 Performance

  1. STS filters utilize a bed of sand as a barrier type of filtration. With uniformly graded silica sand media, filtration performance is predictably 95% of 10 microns and larger as standard. Optional finer uniformly graded silica sand media is available for filtration performance of 90% of 5 microns and larger.

Part 2 - Products

2.01 Manufacturer

  1. The sand filter system shall be manufactured by LAKOS Filtration Systems, a division of Claude Laval Corporation in Fresno, CaliforniaUSA. Specific model designation is: ______

2.02 Filer Tank

  1. All STS filter tanks are made from 304-L stainless steel. Minimum wall and dome thickness for the tank is 14 gauge. Grooved pipe connections are provided at the inlet and outlet. A top inspection port is provided with an epoxy-coated cast iron bolt-on cover. A lower clean-out port is provided with a plastic (PVC) threaded plug.
  1. Maximum system pressure is 100 psi for tank 36” and smaller and 80 psi for 48” tanks.
  1. Outlet & Backwash connections shall be grooved couplings size: ______

D. Pump Inlet connection shall be threaded or flanged

Size: ______

2.03 Backwash & Solids Handling

  1. The evacuation (backwash) of solids that accumulate on the sand bed in the tank may be accomplished automatically, employing electrically actuated butterfly valves using a timer clock to control the frequency and duration of the backwash. The standard timer setting (factory) is to backwash the system for 3 minutes every 24 hours.
  1. The system is also equipped with a pressure differential switch that senses differential pressure in the tank. Differential pressure increases as solids build up on top of the sand bed. Once the differential pressure reaches a certain point (10 psi), the switch will send a signal to start a backwash cycle.
  1. A manual push button is provided on the front of the control panel so that a backwash cycle can be initiated at anytime if necessary.
  1. Multiple tank systems utilize an Alex-Tronix controls system to operate the multiple valves on each tank to ensure that only one tank is backwashing at a time.
  1. The backwash water will need to be piped out to a drain or tank that is adequately sized to accept the quantity of water. The amount of water being backwashed (purged) from the system is based on the filtration surface area, flow rate, number of tanks, and backwash time duration.
  1. STS systems can be provided with either a source or city backwash. Water for the backwash cycle is provided from system water (source), or it is provided by municipal/other (city) water. This water is used by reversing the flow back thru the underdrain to agitate the top layer of the sand bed for removal of solids. The water then pushes the solids out of the tank thru the backwash piping, thus “cleaning” the sand bed and preparing it for another filtering cycle.

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2.04 Underdrain Assembly

  1. Schedule 40 PVC header, PVC internally v-slotted well screen (.010 slot opening size) with minimumcollapse strength of 135 psi. Durability shall be warranted for 15 years.

2.05 Pump

A. End-suction, single stage; TEFC motor; cast iron housing; iron or bronze impeller; bronze shaft sleeve; BUNA-N mechanical shaft seal; flooded suction required. All STS systems are supplied with a cast iron pump strainer with a stainless steel perforated basket.

B. A high head pump option is available for basin sweeping applications.

2.06 Strainer

  1. Provided with system to protect system pump from damage or fouling

by larger solids or debris.

  1. Cast-iron housing; manual-cleaning; 1/8-inch (3.2 mm) minimum mesh

rating; stainless steel basket.

2.07 Piping

  1. Galvanized pipe with grooved coupling.

2.08 Electrical Control

  1. IEC starter with overload module; HOA selector switch; NEMA-4X

Enclosure; re-set/disconnect/trip switch, 120 volt, single phase

control voltage; CSA-approved; UL Listed panel

2.09Backwash Valves

  1. Electrically-actuated valves. Single tank systems use a single actuator with linkage arms to control two butterfly valves (outlet and backwash). Multiple tank systems use multiple actuators to control butterfly valves (outlet and backwash).

2.10 Skid Plate

  1. Stainless steel, 3/16-inch (5 mm) minimum thickness on single tank systems; Epoxy-coated structural steel framework on multiple tank systems.